1. Field of the Invention
This invention relates to a cylinder block of an internal combustion engine, and more particularly to an improvement in a cylinder block of the so-called open-deck type wherein a water jacket fully opens through the cylinder block top surface onto which a cylinder head is secured.
2. Description of the Prior Art
In connection with so-called open-deck type cylinder blocks, a water jacket outer wall is fully spaced from a cylinder-barrel structure at the cylinder block top surface onto which a cylinder head is secured, while the water jacket outer wall is securely connected at a lower block deck with the cylinder-barrel structure. Accordingly, the water jacket outer wall is not rigidly supported at the cylinder head top surface, so that the water jacket outer wall tends to readily vibrate, thereby emitting noise therefrom.